A highly sensitive and visible-light-driven photoelectrochemical sensor for chlorpyrifos detection using hollow Co9S8@CdS heterostructures

A highly sensitive and visible-light-driven photoelectrochemical (PEC) sensor has been constructed for the quantitative assay of organophosphorus pesticides like chlorpyrifos (Chlo) using hollow Co 9 S 8 @CdS heterostructures . The Co 9 S 8 @CdS heterostructures were created by growing CdS onto Co 9 S 8 surface via one-step oil-bath route, of which Co 9 S 8 was fabricated with hollow tubular structures through the Co(CO 3 ) 0.35 Cl 0.2 (OH) 1.1 -templated solvothermal method . It was discovered that the so-obtained Co 9 S 8 @CdS with direct Z-scheme heterojunctions could exhibit larger photocurrents than the Co 9 S 8 or CdS because of the greatly enhanced separation efficiency of photo-generated carriers. What’s more, the photocurrent signal of Co 9 S 8 @CdS-based PEC sensor could be selectively inhibited with the addition of Chlo through the specific chelation between the N and S atoms of Chlo with C N and P S groups and Co sites of Co 9 S 8 @CdS so as to suppress the carriers transferring. The developed PEC sensor could exhibit a linear response for Chlo ranging from 0.050 to 1000 ppb, with the detection limit value down to 0.015 ppb, which was far below than those of currently reported PEC sensors. Besides, the proposed routes may provide guidelines for designing various direct Z-scheme heterojunction-based PEC analysis platforms for determining environmental pollutants like Chlo.